If X is the hundredths digit in the decimal 0.1X and if Y is the thousandths digit in the decimal 0.02Y ,where X and Y are nonzero digits,which of the following is closest to the greatest possible value of 0.1X/0.02Y ?
A. 4
B. 5
C. 6
D. 9
E. 10
D
OG If x is the hundredths digit
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Hi AbeNeedsAnswers,
We're told that X is the hundredths digit in the decimal 0.1X and if Y is the thousandths digit in the decimal 0.02Y and that X and Y are NON-ZERO digits. We're asked which of the following is closest to the GREATEST possible value of 0.1X/0.02Y
To make the value of this positive fraction as large as possible, we need to make the numerator as large as possible AND make the denominator as small as possible... so we should make X = 9 and Y = 1.
.19/.021
To 'clean up' this fraction, let's multiply both the numerator and denominator by 1000....
190/21
At this point, you might find it useful to compare 'multiples' of 21...
(21)(9) = 189
(21)(10) = 210
189 is considerably closer to 190 than 210 is, so that fraction is closest to 9.
Final Answer: D
GMAT assassins aren't born, they're made,
Rich
We're told that X is the hundredths digit in the decimal 0.1X and if Y is the thousandths digit in the decimal 0.02Y and that X and Y are NON-ZERO digits. We're asked which of the following is closest to the GREATEST possible value of 0.1X/0.02Y
To make the value of this positive fraction as large as possible, we need to make the numerator as large as possible AND make the denominator as small as possible... so we should make X = 9 and Y = 1.
.19/.021
To 'clean up' this fraction, let's multiply both the numerator and denominator by 1000....
190/21
At this point, you might find it useful to compare 'multiples' of 21...
(21)(9) = 189
(21)(10) = 210
189 is considerably closer to 190 than 210 is, so that fraction is closest to 9.
Final Answer: D
GMAT assassins aren't born, they're made,
Rich
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To MAXIMIZE the value of 0.1X/0.02Y, we must MAXIMIZE the numerator (0.1X) and MINIMIZE the denominator (0.02Y)AbeNeedsAnswers wrote:If X is the hundredths digit in the decimal 0.1X and if Y is the thousandths digit in the decimal 0.02Y ,where X and Y are nonzero digits,which of the following is closest to the greatest possible value of 0.1X/0.02Y ?
A. 4
B. 5
C. 6
D. 9
E. 10
D
So, the numerator is maximized when X = 9. So, the numerator is 0.19
The denominator is minimized when Y = 1. So, the denominator is 0.021
So, we must determine the value of 0.19/0.021
IMPORTANT: We need not calculate the value of 0.19/0.021
Instead, just recognize that 0.19/0.02 = 9.5, which is halfway between 9 and 10
Since 0.021 is a bit bigger than 0.02, we know that 0.19/0.021 is a bit LESS THAN 9.5
So, 0.19/0.021 must be closest to 9
Answer: D
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Brent
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We are given two decimals:AbeNeedsAnswers wrote: ↑Fri Aug 18, 2017 5:52 pmIf X is the hundredths digit in the decimal 0.1X and if Y is the thousandths digit in the decimal 0.02Y ,where X and Y are nonzero digits,which of the following is closest to the greatest possible value of 0.1X/0.02Y ?
A. 4
B. 5
C. 6
D. 9
E. 10
D
0.1X and 0.02Y
To make 0.1X the greatest, we can let X = 9 and we have:
0.19
To make 0.02Y the smallest, we can make Y = 1 (since Y = 0 is not allowed) and we have:
0.021
Thus:
0.19/0.021 = 190/21 = 9 1/21
So, the greatest possible value is about 9.
Answer: D
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